Make acr's configurable

[phavekes]

Currently the eduID only ACR values are hardcoded.

OpenConext-Invite/server/src/main/java/invite/model/RequestedAuthnContext.java

Lines 7 to 11 in 6e06c3f

	EduIDLinkedInstitution("https://eduid.nl/trust/linked-institution"),
	EduIDValidatedName("https://eduid.nl/trust/validate-names"),
	ValidateNamesExternal("https://eduid.nl/trust/validate-names-external"),
	EduIDRequireStudentAffiliation("https://eduid.nl/trust/affiliation-student"),
	TransparentAuthnContext("transparent_authn_context");

These should live in config, e.g.:

config:
  acr-requirements:
    - acr : "https://eduid.nl/trust/linked-institution"
      description: "Require linked institution"
    - acr: "https://eduid.nl/trust/validate-names"
      description: "Require a validated name" 

If the list is empty of missing, do not show the acr option in the ui.

• Add generic options to config in codebase
• Add to openconext-deploy @phavekes
• Update code to use values from config
• Hide option from ui if unconfigured